Coupling member for electrical distribution tracks

ABSTRACT

A coupling member, for connecting the ends of two lengths of electricity distribution track in which exposed track conductors are mounted, has a pair of conductive contact members which are resiliently mounted within a housing parallel to and insulated from one another, the coupling member being so constructed as to be capable of insertion into the adjacent ends of two lengths of track with contact fingers, provided on the contact members, biased into engagement with the track conductors.

United States Patent [72] Inventors DerekJamesHnrt;

References Cited Robert Davis, both of London, England UNITED STATES PATENTS 827507 2,585,770 2/1952 Hammerly....................

[2]] Appl. No.

9 w ZHW W 3 3 [22] Filed May 26,1969 [45] Patented Aug. 24, 1971 [73] Assignee British Lighting Industries Limited London, England July 22, 1968 Great Britain 34941/68 Assistant Examiner-Robert A. Hafer Attorney-Joseph C. Ryan ABSTRACT: A coupling member, for connecting the ends of two lengths of electricity distribution track in which exposed track conductors are mounted, has a pair of conductive contact members which are resiliently mounted within a housing 339/14 R, parallel to and insulated from one another, the coupling 339/22 B member being so constructed as to be capable of insertion into H0lr 3/06 the adjacent ends of two lengths of track with contact fingers, 339/l4,21, provided on the contact members, biased into engagement 22, 23; 174/99 B with the track conductors.

[32] Priority [54] COUPLING MEMBER FOR ELECTRICAL DISTRIBUTION TRACKS 1 Claim, 1 Drawing Fig.

[51] Int.

[50] Field of PATENTEU AUB24|971 DE REK JAMES HART ROBERT DAVIS BY? Z Cw ATTORNE COUPLING MEMBER FOR ELECTRICAL DISTRIBUTION TRACKS The present invention relates to a coupling member for electrical distribution tracks.

The coupling member is designed to join together the ends of electric distribution tracks in such a way that electrical continuity is established from track to track, without the necessity of making conventional mechanical or soldered electrical connections. The coupling member is especially suitable for joining electrical distribution tracks which carry bare conductor elements, and is particularly, but not exclusively, suitable for use with the track described in our pending application of even date entitled Track for Distribution of Electricity.

According to the present invention, there is provided a coupling member for connecting the ends of separate lengths of electric distribution tracks, comprising a housing in which a pair of conductive contact members is mounted parallel to and insulated from one another, the contact members being so spaced as to be able to engage conductors carried in the tracks, the housing having projections therefrom for engaging with the tracks to locate the coupling member with the contact members abutting the conductors when the coupling member is positioned to connect the tracks.

The coupling member is partially inserted into the end of one length of track, so that part of the member projects from the end of the track. The other end of the coupling member is then inserted into a second length of track. Preferably, the housing is asymmetrical in cross section. The tracks, being also of asymmetrical cross section, can only be connected with the coupling member in one way. Thus reversal of the tracks end-for-end will prevent their connection with the coupling member. In this way, the power supplied by each length of track to appliances through special output adaptors always has the correct polarity. The contact members are so arranged that they abut the conductors carried by the tracks when the coupling member is in position joining two lengths of track. In addition, the coupling member preferably includes a further contact member, which abuts a third conductor carried by each of the tracks when the coupling member-is in position. Continuity between the third conductors, which may form an earth line, is thus established. It will be appreciated that electrical continuity is automatically achieved by mechanical contact of the conductors with the contact members. It is therefore unnecessary to make conventional connections by soldering or by wiring into known devices such as screw-clamping connectors.

The present invention will now be described by way of example with reference to the accompanying drawing which is an exploded perspective view of a coupling member and electric distribution tracks.

As shown in the drawing, the track 10 consists of an elongate member made from an extrusion of a plastics material such as P.V.C. The track has a base 11, and sides 12, 13 extending perpendicularly from the longitudinal edges thereof. The sides 12, 13 include housings for conductor strips 15, 16 which are connected to an electrical supply. The strips are accessible from the inner region of the track 10 by way of slots 19, 20. A third conducting strip 21 is carried by the base 11 of the track 10, and provides an earth line. The sides 12, 13 of the track 10 additionally include flanges 22, 23 which project inwardly from the sides 12, 13 of the track. The flanges extend lengthwise of the track and provide rails on which a coupling member can be positioned.

The coupling member 30 includes a housing 31 in which a pair of contact members 32, 33 is mounted. The housing 31 can be moulded from a rigid plastics material such as P.V.C. lnner walls 34, 35 are located parallel to and spaced apart from one another inside the housing 31. The contact members 32, 33 are secured to the walls 34, 35 on resilient mountings. In the embodiment shown, the resilient mountings comprise plugs or rivets 36 and helical coil springs 37. The contact members 32, 33 are assembled in the housing 31 by passing the plugs 36 through apertures 38 and 39 provided in the housing 31 and the contact members respectively. The apertures 38, 39 are so dimensioned that the plugs 36 are a force fit therein. The helical springs 37 are positioned on the plugs 36 between the inner surfaces of the contact members 32, 33 and the walls 34, 35. It will be appreciated, therefore, that the helical springs 36 bias the contact members 32, 33 away from each other in a lateral direction.

The contact members 32, 33 include portions which are bent out from the members, to form contactfingers 40 which can engage the conductor strips 15, 16 carried by the track 10. It will be appreciated that the contact fingers 40 project outwardly from the sides of the housing 31. Each contact member has two such contact fingers, which are separated from one another by a slot 41. The contact members can be made from a material such as copper.

The housing 31 additionally carries a further contact strip 42, which is positioned between the walls 34, 35 The contact strip 42 is secured to a spacer 43, attached to the walls 34, 35, by'means of a conventional pop rivet 44 which is passed through apertures 45 and 46 in the contact strip 42 and the spacer 43. The contact strip 42 is provided to establish continuity between the earth line conductors 21 carried by the tracks 10. The strip 42 can be made from a spring steel.

It will be seen from the drawing that, in cross section, the tracks 10 are asymmetrical about a central plane parallel to the sides 12, 13. In particular, adjacent side 12 there is a groove 47 and adjacent the side 13 the base includes a surface 48 which is inclined towards the conductor strip carried by the side 13. The housing 31 of the coupling member is so shaped that it can only be inserted into the end of the track 10 in one way. Thus, the housing 31 includes, when viewed in plan a square comer A, which will project into the groove 47 of the track when the coupling member is positioned in the end of the track. The opposite corner B of the housing 31 is inclined corresponding to the inclined surface 48 of the base 11. 1f the coupling member 30 were reversed end-for-end, the square comer A would abut the track in the zone of the inclined surface 48, and prevent the insertion of the coupling member 30. When the coupling member has been correctly inserted in the end of one length of track, a second length of track can be I connected to the coupling member. It will be appreciated that only one end of the second track will fit over the coupling member, owing to their a symmetry. When connected to a supply line, the polarity of, for example the track conductor 16, adjacent the groove 47 in the base 11, will be identical from track to track. The power supplied to appliances through similarly-asymmetrical track output connectors will therefore be of the correct polarity. The housing 31 is additionally provided with projections 49 which rest on the flanges 22, 23. The projections 49 are so positioned relative to the contact fingers 40 that when the coupling member is positioned on the track, the contact fingers 40 can engage the track conductors. In addition, the housing 31 includes further projections in the form of lugs 50. The lugs 50 are so positioned that, on inserting the coupling member 30 into the track 10, the lugs can abut the ends of the track conductors 15, 16. Movement of the coupling member 30 into the track will then move the track conductors 14, 15 away from the end of the track. This ensures that the track conductors cannot be accidentally touched, and furthermore avoids electrical tracking between the conductors and a mating metal cover track.

As will be seen from the drawing, the earthing strip 42 is provided with apertures 52. The apertures 52 include raised circumferential lips. When the coupling member 30 is inserted into the track 10, the raised lips of the apertures 52 contact the third conducting strip 21 of the track 10, bending the earthing strip 42 downwards as viewed in the drawings. A countersunk portion is formed in the strip 21, to accept the raised lips of the corresponding aperture, when the coupling member 30 is inserted to the requisite distance into the track 10.

To connect two lengths of track 10, the coupling member 30 is inserted into the end of one track. As explained, the coupling member 30 can be inserted into the ends of lengths of track in one way only. The housing 31 is so positioned relative to the track that the underside of the projections 49 coincide with the top surface of the flanges 22, 23 of the track. The contact members 32, 33 are moved towards each other, and the coupling member is inserted into the end of the track. The contact members 32, 33 are then released. The projections 49 are so located that when the contact members are released, the contact fingers 40 pass through the passages 19, to abut the conductor strips 15, 16. Efficient electrical contact between the fingers 40 and the conductor strips 15, 16 is maintained by means of the biasing of the contact members 32, 33 provided by the springs 37. When the coupling member has been fully inserted in the tracks, the contact fingers 40 of the contact members 32, 33 are completely housed within the track 10. Thus the contact members cannot be touched accidentally. The other length of track is then connected to the coupling member in a similar manner.

Once the coupling member is positioned between two lengths of track, it can be locked in place by means of fixing screws 51 which extend through the apertures 52 provided in the spring steel earthing strip 42. The coupling member thus provides simple electrical connection between separate lengths of electrical distribution track. When positioned, the

coupling member automatically connects the conductors carried in the track thereby eliminating conventionally formed connections. The correct polarity is ensured from track to track since the coupling member can be positioned in the tracks in one way only.

We claim:

1. A coupling member for connecting the ends of separate lengths of electricity distribution tracks which carry exposed track-conductors, the coupling member comprising:

a housing, 1

a pair of conductive contact members mounted parallel to and insulated from one another in said housing, track-locating projections on the external surfaces of said housing,

said locating projections positioning the coupling member,

when connected between two lengths of track, with its conductive contact members abutting the said track-conductors, and

further projections located to abut the ends of the track conductors when the coupling member is in position for connecting two lengths of track, whereby relative movement between the coupling member and the two lengths of track is transmittedto the track conductors to move them longitudinally away from the adjacent ends of the two lengths of track. 

1. A coupling member for connecting the ends of separate lengths of electricity distribution tracks which carry exposed trackconductors, the coupling member comprising: a housing, a pair of conductive contact members mounted parallel to and insulated from one another in said housing, track-locating projections on the external surfaces of said housing, said locating projections positioning the coupling member, when connected between two lengths of track, with its conductive contact members abutting the said track-conductors, and further projections located to abut the ends of the track conductors when the coupling member is in position for connecting twO lengths of track, whereby relative movement between the coupling member and the two lengths of track is transmitted to the track conductors to move them longitudinally away from the adjacent ends of the two lengths of track. 